KR100673815B1 - Optically anisotropic device - Google Patents

Abstract

Provides an optically anisotropic element with excellent display and mechanical properties such as contrast and clock characteristics.

An optically anisotropic element is comprised with an optically anisotropic film and a light-diffusion adhesive layer.

Optically anisotropic element

Description

Optically anisotropic element {OPTICALLY ANISOTROPIC DEVICE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optically anisotropic element with remarkably improved display characteristics such as contrast and visual characteristics, and to a significant improvement in mechanical properties, and a twisted nematic liquid crystal display device in which the optically anisotropic element is disposed.

Twisted nematic liquid crystal display device (hereinafter abbreviated as TN-LCD) of active driving using TFT element or MIM element adds the original characteristics of LCD such as thin type, light weight and low power consumption. Image quality comparable to CRT. For this reason, it is widely used as a display device for notebook computers, portable televisions, portable information terminals, etc. However, in conventional TN-LCDs, the display color changes when viewed obliquely due to refractive index anisotropy having liquid crystal molecules or a display control. The problem of the viewing angle that the trail is lowered is inherently inevitable, and the improvement is strongly desired, and various attempts for improvement have been made.

Recently, various optical compensation films have been proposed for the purpose of solving the viewing angle problem, and the development of the TN-LCD characterized by the wide viewing angle is remarkable. For example, Japanese Patent Application Laid-Open Nos. 4-349424 and 6-250166 disclose an optical compensation film using a cholesteric film inclined with a spiral axis and a liquid crystal display device using the same. Also, Japanese Patent Laid-Open Nos. 5-249547 and 6-331979 have proposed LCDs using a negative ('-') uniaxial compensator with an inclined optical axis, and a multi-layer thin film compensator is used as a specific embodiment. In Japanese Patent Laid-Open Publication No. 10-186356, Japanese Patent Laid-Open Publication No. 10-206637, and the like, an optical compensation film obtained by immobilizing a liquid crystal exhibiting positive uniaxial uniaxial property by nematic hybrid orientation and using the same Liquid crystal displays have been proposed. Moreover, Japanese Patent Application Laid-Open No. Hei 8-50206 and the like have proposed an optical compensation film made of discotic liquid crystal molecules showing an optically negative uniaxial property and a liquid crystal display device using the same, and by using these optical compensation films, conventional liquid crystal displays are proposed. Compared with the device, the viewing angle characteristic can be significantly improved. In addition, because of advances in LCD technology, optical devices combining optical compensation films and light diffusion layers, which need to meet the demands of wide viewing angles, can satisfy the wide viewing angles. have.

For example, Japanese Patent Laid-Open No. 10-104611 discloses a liquid crystal display device in which optical compensation means are provided on both sides of a driving liquid crystal cell and a light diffusion layer is provided on the light exit surface side of the liquid crystal cell portion. In this publication, by providing the light diffusing layer on the light exit side of the polarizing plate, the wide viewing angle is realized by the light emitted through the polarizing plate being diffused in all directions by the light diffusing layer. Further, Japanese Patent Laid-Open No. 10-142591 proposes a liquid crystal display device having an optically anisotropic film and a light diffusing film that exhibit negative uniaxiality.

However, for example, as described in Japanese Patent Application Laid-Open No. 10-104611, when a light diffusing layer is provided on the light exit side, the light diffusing layer is provided on the outermost surface of the LCD, so that anti-glare treatment is performed in addition to light diffusing. It is necessary to perform antireflection treatment, impart hard coat property to the surface, impart light resistance, and the like, and there is a problem that the manufacturing cost becomes high. In addition, as described in Japanese Patent Application Laid-Open No. 10-142591, when the optically anisotropic film and the light diffusing film are laminated, the thickness of the optical member is increased and the thin film, which is one of the characteristics of the LCD, is damaged. On the other hand, when bonding an optical element containing a polarizing plate to a liquid crystal cell, there exists a possibility that the thickness of an optical element may become thick, and the problem that it cannot process with an existing bonding machine may arise. In addition, when the above-mentioned optical element is provided between the polarizing plate and the liquid crystal cell, the film is peeled off between the light diffusing film and the polarizing plate or between the light diffusing film and the viewing angle improving film when left at high temperature or high temperature and high humidity. There was a possibility of causing a problem, and there was a problem regarding the mechanical properties in the reliability test and the like. The content of the well-known example mentioned above is added here as a reference.

<Object of invention>

This invention solves the said subject, and combines a specific optically anisotropic film and a light-diffusion adhesive layer, and changes the viewing angle characteristic of a TN-LCD, without changing the manufacturing process of a TN-LCD. The present invention provides an optically anisotropic element with improved mechanical properties and a twisted nematic liquid crystal display device having the optically anisotropic element.

<Summary of task>

That is, the 1st of this invention relates to the optically anisotropic element comprised from the optically anisotropic film (A) and at least 1 layer of light-diffusion adhesive layers (B).

Moreover, 2nd of this invention relates to the optically anisotropic element characterized by the said optically anisotropic film (A) which is an optically anisotropic film which consists of liquid crystal molecules which show positive uniaxiality or negative uniaxiality.

The third aspect of the present invention also relates to an optically anisotropic element, wherein the optically anisotropic film (A) is formed of low molecular weight and / or high molecular liquid crystal.

Moreover, 4th of this invention is related with the optical laminated body comprised from the said optically anisotropic element and a polarizing plate.

A sixth aspect of the present invention also provides a twisted nematic liquid crystal display device comprising at least a driving liquid crystal cell comprising a pair of transparent substrates having an electrode and a nematic liquid crystal, an upper polarizing plate and a lower polarizing plate disposed above and below the liquid crystal cell. A twisted nematic liquid crystal, wherein at least one of the optically anisotropic elements is disposed between one of the upper and lower polarizing plates of the liquid crystal cell or between the liquid crystal cell and each of the upper and lower polarizing plates. It relates to a display element.

<Embodiment of the invention>

Hereinafter, the present invention will be described in more detail.

The optically anisotropic element of the present invention significantly improves the visual characteristics of the TN-LCD and has excellent mechanical characteristics.

TN-LCDs are classified into a driving method, such as a simple matrix method, a TFT (Thin Film Trasistor) electrode using an active element as an electrode, an active matrix method using a metal insulator metal (MMD) or a thin film diode (TFD) electrode, and the like. It can be broken down together. The optically anisotropic element of this invention has an effect also in any drive system.

In addition, the halftone gray scale method (pixel division method) and domain division method, which are known techniques, can be considered as an attempt to expand the viewing angle of the LCD toward the driving liquid crystal cell. In addition, the optically anisotropic element of the present invention can effectively expand the viewing angle.

The optically anisotropic element of this invention consists of an optically anisotropic film (A) and at least 1 layer of light-diffusion adhesive layer (B).

The optically anisotropic film (A) is not particularly limited as long as the optically anisotropic film has optically anisotropy. For example, a stretched film obtained by stretching a liquid crystal film or a polymer film in which an alignment state of liquid crystal is immobilized can be used. Especially, the liquid crystal film which consists of liquid crystal molecules optically showing positive or negative uniaxiality is preferable, Furthermore, the optically positive or negative uniaxiality which immobilized the hybrid orientation state which the liquid crystal molecule changed to the film film direction after It is preferable to use the liquid crystal film which shows the as an optically anisotropic film (A) from the point of TN-LCD viewing angle improvement effect.

The liquid crystal film in which the hybrid alignment state is immobilized can be obtained by forming a liquid crystal material capable of forming a nematic hybrid orientation. As the liquid crystal material, for example, a liquid crystal compound or a liquid crystal composition which can exhibit positive or negative uniaxiality regardless of molecular shape such as rod-shaped or disc-shaped, low molecular weight or polymer. Means. As the liquid crystal material, either lyotropic or thermotropic properties can be used.

Specific examples of the liquid crystal substance include low-molecular liquid crystals such as biphenyl derivatives, phenylbenzoate derivatives, styrene derivatives, triphenylene derivatives, and truncene derivatives, such as polyesters, polyamides, polycarbonates, polyester imides, and the like. Side chain type polymer liquid crystals, such as a main chain type | mold polymer liquid crystal, polyacrylate, polymethacrylate, polymaronate, and polysiloxane, etc. are mentioned.

As the optically anisotropic film (A) formed of the low molecular liquid crystal, the liquid crystal molecules can be nematically hybridized, and the alignment state can be obtained by immobilization by glass immobilization, immobilization by thermal or photocrosslinking reaction, or the like. It is preferable to use a liquid crystal film as an optically anisotropic film (A). Here, the film obtained by hybrid orientation fixation of rod-like liquid crystals represented by biphenyl derivatives, phenylbenzoate derivatives, styrene derivatives, or the like is an optically anisotropic film (a1) composed of liquid crystal molecules showing optically positive uniaxiality. The film obtained by hybrid orientation fixation of the disk-shaped liquid crystal represented by a natrexen derivative etc. can be obtained as an optically anisotropic film (a2) which consists of liquid crystal molecules optically showing negative uniaxiality. As an optically anisotropic film (a1), it can obtain by the method as described in W097 / 44702, etc., for example. The optically anisotropic film a2 can be obtained, for example, by the method described in Japanese Patent Laid-Open Nos. 8-50206 and 8-334621.

Subsequently, as said polymeric liquid crystal, the nematic hybrid orientation was formed especially, and as a result, the orientation property is good and the liquid crystalline polyester which is comparatively easy also is preferable. Specifically as liquid crystalline polyester, the aromatic group which has a bulky substituent in the structural unit which comprises a main chain as described, for example in Unexamined-Japanese-Patent No. 10-186356, Unexamined-Japanese-Patent No. 10-206637, long chain, (長 鎖) Homeotropic oriented liquid crystalline polyester which has an aromatic group which has an alkyl group, an aromatic group which has a fluorine atom, etc., C3-C20 long-chain alkyl group or C2 at the terminal or the distal end of a polymer chain Homeotropic oriented liquid crystalline polyesters having a long-chain fluoroalkyl group of 20 and the like and having a monofunctional structural unit derived from a compound having one functional site such as monoalcohol or monocarboxylic acid; What is made into an essential component is mentioned. In general, the main chain of the liquid crystalline polyester is formed of a bifunctional structural unit such as a dicarboxylic acid unit, a diol unit, and an oxycarboxylic acid unit or a polyfunctional structural unit other than the unit, but as the liquid crystalline polyester, It is more preferable to have an allosubstituted aromatic unit in the main chain. Specifically, a catechol acid unit, a salicylic acid unit, a phthalic acid unit, a 2, 3-naphthalene diol unit, a 2, 3-naphthalene dicarboxylic acid unit, and those which have a substituent in these benzene rings are mentioned.

As the optically anisotropic film (A) formed of the above-mentioned polymer liquid crystal, the optically defined one can be obtained by hybridly aligning the liquid crystal molecules and immobilizing the alignment state by glass immobilization, immobilization by thermal or photocrosslinking reaction, or the like. It is preferable in this invention to use the film which consists of liquid crystal molecules which show axiality as an optically anisotropic film (a3). In addition, the optically anisotropic film (a3) can be obtained by solution coating a polymer liquid crystal onto an alignment substrate, such as the method described in the above publication, by a solvent preparation method, heat treatment, and then cooling. Various conditions of the selection of the solution, the solvent preparation method, the heat treatment, and the cooling are determined in consideration of the kind of the polymer liquid crystal to be used and the optical parameters of the nematic hybrid orientation desired.

The optically anisotropic film (a1), (a2) or (a3) transfers the liquid crystal film to a transparent substrate film different from the alignment substrate (alignment substrate / (alignment film) / liquid crystal film) as formed on the alignment substrate. If one form (transparent substrate film / liquid crystal film) or the liquid crystal film has self-supporting property, either form of liquid crystal film monolayer (liquid crystal film) can be used as the optically anisotropic film (A).

As said transparent substrate film, For example, the triacetyl cellulose film marketed by brand names, such as Fuji Tak (made by Fuji photo film) and Konica Tak (made by Konica), or TPX film (made by Mitsubishi Chemicals), an aton film (Japan synthesis) The film etc. which are marketed by brand names, such as rubber | gum), a Xeon nets film (made by Japan Xeon), and an acriple film (made by Mitsubishi Rayon), are mentioned.

As a transfer method, for example, as described in Japanese Patent Application Laid-Open Nos. 4-57017 and 5-333313, an adhesive is applied to the liquid crystal film layer, and another substrate film different from the alignment substrate is laminated. After curing the adhesive and peeling the alignment substrate from the film laminate, a method of transferring only the liquid crystal film can be used. This method should be adopted when an optically opaque film such as a rubbing polyimide film or a rubbing polyethylene terephthalate film or an opaque film in the visible wavelength range is used as the alignment substrate.

Next, the light-diffusion pressure-sensitive adhesive layer (B) is not particularly limited as long as it has a property of isotropically or anisotropically diffusing incident light and has adhesiveness. As said light-diffusion adhesive layer, the sheet-like thing, film-like thing, etc. which do not have self-supportability which the particle | grains which have refractive index different from a matrix disperse | distributed in the matrix which have adhesiveness are mentioned, for example. Specifically, a matrix composed of an acrylic pressure sensitive adhesive, a rubber pressure sensitive adhesive, a silicone pressure sensitive adhesive, an ethylene vinyl acetate copolymer type pressure sensitive adhesive, a urethane pressure sensitive adhesive, a vinyl ether pressure sensitive adhesive, a polyvinyl alcohol pressure sensitive adhesive, a polyacrylamide pressure sensitive adhesive, and a mixed pressure sensitive adhesive thereof, etc. For example, organic fine particles such as polystyrene fine particles and polymethacrylic acid fine particles having an average particle diameter of 0.5 to 5 µm, silica, alumina, titania, zirconia, tin oxide, indium oxide, cadmium oxide, and antimony oxide The dispersion | distribution of suitable things, such as the inorganic type microparticles | fine-particles, the air microparticles | fine-particles containing gas, and the microcapsule containing liquid, are illustrated. As a matrix, an acrylic adhesive is especially preferable because it is excellent in transparency, weather resistance, heat resistance, etc. Moreover, when obtaining the superimposition layer of a light-diffusion adhesive layer (B), it can be set as the same kind or a combination of different types.

As said acrylic adhesive, a well-known suitable acrylic adhesive can be used. For example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group, isobutyl group, amyl group, isoamyl group, hexyl group, heptyl group, cyclohexyl group, 2-ethyl Straight chain of 1 to 18 carbon atoms such as hexyl group, octyl group, isooctyl group, nonyl group, isononyl group, decyl group, undecyl group, lauryl group, tridecyl group, tetradecyl group, stearyl group and octadecyl group The pressure sensitive adhesive etc. which mainly use the acrylic polymer which used the 1 type (s) or 2 or more types of the acrylic acid type alkyl ester which consists of ester of acrylic acid and methacrylic acid which have a linear or branched alkyl group are mentioned.

Moreover, in the said light-diffusion adhesive, in the range which does not impair the effect of this invention, for example, petroleum resin, rosin type resin, telpen type resin, synthetic petroleum resin, phenol resin, xylene resin, alicyclic ( Iii) tackifiers such as petroleum resins, coumarone indene resins, styrene resins, dcclopentadiene resins, softeners such as phthalic acid esters, lean acid esters, paraffins, polybutenes, and polyisobutylenes; Appropriate additives, such as various other fillers, antioxidant, crosslinking agent, can be mix | blended.

Using such a light-diffusion adhesive, the optically anisotropic element which consists of an optically anisotropic film (A) and a light-diffusion adhesive layer (B) is obtained.

An appropriate method can be used as a manufacturing method of an optically anisotropic element. For example, a solution with a suitable organic solvent such as toluene or ethyl acetate, or a solid dispersion made from a dispersion or an emulsion with water is usually adjusted to a light diffusion adhesive solution of about 10 to 40% by weight. A method of directly laying on an optically anisotropic film by an appropriate development method such as an industrial method, or a method of applying a light-diffusion adhesive made of a mixture of monoma components or the like to an optically anisotropic film and irradiating the separator, or according to the above. The method of bonding the light-diffusion adhesive layer formed in this on the optically anisotropic film etc. are mentioned. Therefore, the superimposition layer of a light-diffusion adhesive layer can also be formed by the appropriate method, such as a superposition method and a bonding superposition method. Moreover, when providing an overlapping light-diffusion adhesive layer on both surfaces of an optically anisotropic film, it can be set as light-diffusion adhesive layer, such as another composition or a kind, in the front and back of an optically anisotropic film. Furthermore, the optically anisotropic film surface on which the light-diffusion pressure-sensitive adhesive layer is deposited may be provided on one or more layers on each of the liquid crystal film layer surface, the alignment substrate surface, and the supporting film surface different from the cladding substrate.

Although the film thickness of a light-diffusion adhesive layer (B) is not specifically limited, Usually, 1 micrometer-100 micrometers, Preferably they are 5 micrometers-50 micrometers, More preferably, they are 10 micrometers-30 micrometers.

Moreover, the total light transmittance of a light-diffusion adhesive layer (B) is 50% or more normally, Preferably it is 60% or more, More preferably, it is 70% or more. Moreover, the diffusion transmittance of this light-diffusion layer is 10%-90% normally, Preferably it is 20%-75%, More preferably, it is 30%-60%.

The optically anisotropic element of the present invention can be suitably used as a viewing angle improving member such as a twisted nematic liquid crystal display element, but in that case, when the display element is accompanied by a polarizing plate, the optically anisotropic element may be provided as a laminate with the polarizing plate. have.

As a manufacturing method of the laminated body which consists of a polarizing plate and an optically anisotropic element, the method of using the light-diffusion adhesive layer (B) demonstrated previously for lamination | stacking with a polarizing plate, and another adhesive layer or an adhesive layer between a polarizing plate and an optically anisotropic film (A) There is a method of laminating it by inserting it. In consideration of the simplification of the manufacturing process and the reduction in cost, the method of using the light-diffusion pressure-sensitive adhesive layer for lamination with the polarizing plate is more preferable. The adhesive is not particularly limited as long as it is an optical grade, but for example, acrylic, epoxy, ethylene-vinyl acetate copolymerization system, urethane series, and mixtures thereof can be used. Moreover, these adhesives can be used without any problem, such as a thermosetting type, a photocuring type, and an electron beam curing type.

Moreover, after providing a light-diffusion adhesive layer (B) to a polarizing plate according to the above-mentioned method, it is comprised by an optically anisotropic film and a light-diffusion adhesive layer by sandwiching the said light-diffusion adhesive layer and laminating an optically anisotropic film (A). The laminate of substantially the same form as the laminate of the optically anisotropic element and the polarizing plate can be produced.

As said polarizing plate, although the suitable polarizing plate which has a polarizing function can be used, what consists of a polarizing film is generally used. In this case, there is no restriction | limiting in particular about a polarizing film, For example, oxo to a hydrophilic polymer film, such as a polyvinyl alcohol film, a partially formalized polyvinyl alcohol film, an ethylene-vinyl acetate copolymerization partial kenation film, or a cellulose film And / or a polyene oriented film such as a film stretched by adsorbing a dichroic dye, a dehydration product of polyvinyl alcohol, or a dehydrochlorination product of polyvinyl chloride. Although the film thickness of a polarizing film is 5 micrometers-80 micrometers normally, it is not limited to this. Furthermore, a polarizing film may be sufficient as a polarizing plate, and the thing which provided the transparent protective layer on one side or both sides of a polarizing film may be sufficient. The transparent protective layer is not particularly limited as long as the transparent protective layer is excellent in transparency, mechanical strength, thermal stability, moisture shielding, and the like, and for example, polyester resin, polyether sulfone resin, polycarbonate resin, polyamide resin, Suitable ones such as polyimide resin, polyolefin resin, acrylic resin, acetate resin, cellulose resin, or thermosetting or ultraviolet curing resin such as acrylic, urethane, acrylic urethane, epoxy, silicone or the like can be used.

Formation of the liquid crystal display element using the optically anisotropic element of this invention can be performed according to a well-known technique. In other words, a liquid crystal display device generally includes a pair of transparent substrates having electrodes and a twisted nematic type driving liquid crystal cell composed of nematic liquid crystals, a polarizing plate, an illumination system, and the like, by assembling a drive circuit by appropriately assembling necessary components. The optically anisotropic element of the present invention may be formed, except that at least one of the liquid crystal cell and the upper or lower polarizing plate is disposed between the one or between the liquid crystal cell and each of the upper and lower polarizing plates. There is no restriction in particular. Moreover, when using the liquid crystal film which fixed the nematic hybrid orientation as the optically anisotropic film (A) which comprises the optically anisotropic element of this invention as mentioned above, since the upper and lower sides of this film are not optically equivalent, also in an optically anisotropic element, The upper and lower sides are not optically equivalent. Therefore, which of the light-diffusion pressure-sensitive adhesive layer (B) and the optically anisotropic film (A) is disposed on the cell side, or which is placed on both sides, which is the case where the pressure-sensitive adhesive layer (B) is superimposed on one side, for example. In the same case, the viewing angle improvement effect of the liquid crystal display device differs depending on the optical properties of the optically anisotropic film, the configuration and arrangement of the optically anisotropic element, such as which one is disposed on the cell side. In the present invention, the configuration of the optically anisotropic element and the top and bottom of the optically anisotropic element are not particularly limited to the liquid crystal cell for driving. It is necessary to equip the liquid crystal display device with the optical anisotropic element of the present invention in consideration of the cell parameters and the required optical performance of the equipped liquid crystal display device.

1 is a cross-sectional view showing an example of a liquid crystal display device using the optically anisotropic element of the present invention.

Fig. 2 is a graph showing the measurement results of the transmittance in the vertical direction in each gradation of the liquid crystal display device in Example 1;

3 is a graph showing the measurement results of transmittance in a control example in Example 1. FIG.

4 is a cross-sectional view showing one example of a configuration in which a laminate is bonded to glass by sandwiching an adhesive layer.

FIG. 5 is a cross-sectional view showing an example of a configuration in which a laminate is bonded to glass by sandwiching an adhesive layer. FIG.

Explanation of the code | symbol in drawing is

1, 11 polarizing plate 2 Diffusion adhesive layer

3, 9 optically anisotropic film 4, 8, 10 pressure-sensitive adhesive layer

5, 7 Glass Substrate 6 Liquid Crystal

12 Glass 13 Light Diffusion Sheet

14 Adhesive layer or UV curable adhesive layer

Although an Example is described below, this invention is not limited to this.

Example 1

According to the Example of Unexamined-Japanese-Patent No. 10-186356, the optically anisotropic film which consists of liquid crystal molecules which shows positive uniaxiality was produced. Subsequently, on the separator (polyethylene terephthalate film), the light-diffusion adhesive layer (90.1% of total light transmittance, 47.1% of diffuse transmittance) which disperse | distributed polystyrene microparticles | fine-particles to the acrylic adhesive was formed, and the light-diffusion adhesive layer was used as one of the optically anisotropic films. It bonded to the surface and the optically anisotropic element was produced.

Using this optically anisotropic element, a liquid crystal display device was produced in the arrangement as shown in FIG. ZLI-4792 was used as a liquid crystal material for the used TN type drive cell, and cell parameters are 4.8 micrometers of cell gaps, 90 degree of twist angle (left twist), and 4 degree of pretilt angles. A voltage of 0 V to 6 V was applied to the liquid crystal cell, and the transmittance in the vertical direction in each gradation was measured using a color luminance meter BM-5 manufactured by Topcon Corporation. The results are shown in FIG. In addition, the same measurement was performed about the liquid crystal display device at the time of using only the optically anisotropic film used by this embodiment for comparison, and the result was shown in FIG. In the case of the optically anisotropic film alone, gray scale inversion occurred when the angle formed between the normal line and the line of sight of the liquid crystal cell from the lower side of the liquid crystal cell was 20 degrees. On the other hand, when the optically anisotropic element of the present embodiment was used, gradation inversion did not occur even at a viewing angle of -60 °.

Moreover, in order to investigate the mechanical characteristic at the time of holding an optical element under high temperature, high temperature, and high humidity, the laminated body of the form which bonded together the said optically anisotropic film and polarizing plate by sandwiching the light-diffusion adhesive layer was produced.

Example 2

According to the Example of WO97 / 44702, the optically anisotropic film which consists of liquid crystal molecules which shows positive uniaxiality was produced. Based on Example 1, the laminated body which is the form of this Example which bonded this optically anisotropic film and a polarizing plate together by sandwiching the light-diffusion adhesive layer was produced.

Example 3

Based on the Example of Unexamined-Japanese-Patent No. 8-50206, the optically anisotropic film which consists of liquid crystal molecules which show negative uniaxiality was produced. Based on Example 1, the laminated body which is the form of this Example which bonded this optically anisotropic film and a polarizing plate together by sandwiching the diffusion adhesive layer was produced.

Comparative Example 1

The optically anisotropic film of Example 1 and the light-diffusion film (IDS-16 by the Nippon Print Co., Ltd.) were bonded together using the commercial epoxy-type ultraviolet curing adhesive. The adhesive layer was sandwiched in the light-diffusion film surface, and the polarizing plate was bonded together.

Comparative Example 2

The optically anisotropic film of Example 2 and the light-diffusion film (IDS-16 by Nippon Printing Co., Ltd.) were bonded together using the non-career adhesive made from Pacheon Paper Co., Ltd. The adhesive layer was sandwiched in the light-diffusion film surface, and the polarizing plate was bonded together.

Comparative Example 3

The optically anisotropic film of Example 3 and the light-diffusion film (IDS-16 by Nippon Printing Co., Ltd.) were bonded together using a commercially available epoxy-type ultraviolet curing adhesive. The adhesive layer was sandwiched in the light-diffusion film surface, and the polarizing plate was bonded together.

(Durability test)

The laminated bodies of Examples 1-3 and Comparative Examples 1-3 were bonded together to glass by sandwiching an adhesive layer. The structure at the time of bonding to glass is shown to FIG. 4 and FIG. The laminated body bonded to this glass was put into 90 degreeC, a dry thermostat, 60 degreeC, and a 90 degreeC constant temperature / humidity tank, and peeling was carried out for 500 hours. The results of this durability test are summarized in Table 1.

Table 1) Results of durability test of laminates of Examples 1 to 3 and Comparative Examples 1 to 3

Since the optically anisotropic element of the present invention is composed of an optically anisotropic film and a light diffusing pressure-sensitive adhesive layer, the optical characteristics of the twisted nematic type liquid crystal display device are markedly improved and the mechanical characteristics are improved. It can be greatly improved, and its industrial use value is extremely high.

Claims (5)

Optically anisotropic film (A) obtained by orienting liquid crystal molecules showing positive uniaxiality and fixing the alignment state, and a light diffusing pressure-sensitive adhesive layer having a total light transmittance of 50% or more and a diffusion transmittance of 10 to 90%. An optically anisotropic element comprising (B). delete The optically anisotropic element according to claim 1, wherein the optically anisotropic film is formed of low molecular weight and / or high molecular liquid crystal. The optical laminated body according to claim 1, comprising an optically anisotropic element and a polarizing plate. The twisted-needm according to any one of claims 1 to 3, comprising a driving liquid crystal cell comprising a pair of transparent substrates having an electrode and a nematic liquid crystal, an upper polarizing plate disposed above and below the liquid crystal cell, and a lower polarizing plate. A tick type liquid crystal display device, wherein an optically anisotropic element is further disposed between either one of the upper or lower polarizing plate of the liquid crystal cell, or between the liquid crystal cell and each of the upper or lower polarizing plate. Ted nematic liquid crystal display device.

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